Mercury tube and circuit therefor



Dec. 2, 1947. A, VANG' 2,432,051

MERCURY TUBE AND CIRCUIT THEREFOR Filed May 19, 1944 Sheets-Sheet 1 15c I A 20 I? r\ Z0 G) I! 20 CD INVENTOR. AA FRED VANG.

BY mm a ATTORNEK Dec. 2, 1947. VANG 2,432,051

MERCURY TUBE AND CIRCUIT THEREFOR Filed May 19, 1944 2 Sheets-Sheet 2 IN VEN TOR.

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Patented Dec. 2, 1947 iiNiTED' STATES- PATENT OFFICE MERCURY TUBE AND CIRCUIT THEREFOR;

Alfred Vang, New York, N. Y.

Application May 19, 1944, Serial No. 536,341 Claims. (01'. 250- 275) This invention relates to new and useful improvements in mercury arc tubes and circuits therefor, and more particularly it pertains" to improvements in such tubes and circuits as shown in my Patents 2,287,540; 2,287,541; 2,287,542; 2,287,543 and 2,287,544.

Thus one object of the invention is to provide an improved tube of this kind which has a low center of gravity and does not require complicated mounting means for holding it in place, which may be subjected to uneven expansion and lead to a breakage of'thetubes.

Another object of the invention is to provide a tube that will withstand higher'potential dinerences.

Further objects of the invention are'to provide an improved device of this kind which can be manufactured by standard glass blowing equipment, and provides flexibility of use in various types of circuits where space is small, but will afford a large surface for the dissipation of heat, and to provide simple circuits for self-ignition of the tubes.

Additional objects of the invention are to efiect simplicity and efliciency in such apparatus and to provide a simple device or apparatus of this kind which is economical, durable, and reliable in operation, and economical to manufacture and ins all.

Still other objects of the invention will appear as the description proceeds; andwhile herein details of the invention are described in the specification and some of the claims, the invention as described in the broader claims is not limited to these, and various changes may be made Without departing from the scope of the invention, as claimed herein.

The inventive features for the accomplishment of these and other objects are shown herein in connection with a mercury arc tubewhich briefly stated, includes an envelope comprising a hollow portion containing a pool of mercury. From said portion projects a hollow duct-forming arm on which is mounted a hollow bulb likewise containing a pool of mercury. The pools are in. electrical contact only through: controlled ionized mercury vapor Within the envelope and in contact with said pools, and are ignited by internal or external igniters.

In the accompanying drawing showing, by way of example; several of many possible embodiments of the invention:

Figure 1 is a side elevation showing one form of the tube.

Figure 2 is 83 fragmented pllrilshowin'g external igniter on the envelope;

Figure 3 is a schematic representation of the tube and conventional igniter;

Figure 4 is a side elevation showing another form of the tube.

Figure 5 is a planrview showingstill another form of the tube.

Figure 6 is a wiring diagram showing one tube for full-wave rectification',-. and anothertube as a discharge tube;

Figure 7 is a wiring diagram for full-wave rectification of the 3-phase current; and

Figure 8 is a wiring diagram showing one end of the tube for use as a rectifier, and the other half for discharge.

My rectifying or discharge tube, as shown in Figures 1 and 2, comprises an envelope Illa of heat resisting insulating material, such as glass, having a substantially spherically shaped hollow portion lla, normally the cathode portion when the tube is used as a rectifier. A hollow cylindrical arm I2 is developed'on'said portion and forms a duct communicating with the interior of the hollow portion Ha and in communication with the interior of a hollow ball or anode portion. [4 on the outer end of the arm. A pool of mercury I5 is disposed in the depression or pocket of said hollow portion H0 and a similar pool IS in said ball l4; that in the former beinga cathode and that in the latter being an anode; the ductbeing at a higher level'than' the upper level of the pools, so that the pools are electrically separated, except by controlled ionized gas conduction through rarified mercury vapor in the envelope and external terminals IS, IS; said gas passing through th envelope and provides direct contact with each of the pools;

The interior of the arm l2 is'prefer'ably provided with a hump or dividing ridge IT in" the middle portion ofthe arm at-the' bottom of the duct, the duct sloping downwardly at each end. The slopes of the'duct on each side ofthe hump enable any mercury that tends to accumulate on the walls of the duct to drain back into the respective pools. The-slopes'of the ductpermit substantially equal distribution of the mercury between the pools, even though one of 'the pools be higher than the other.

In the commercial manufacture of my'tubes, the length of the armcanbeeasily varied, since thearm may be made from tube stock. For producing long arms a longer section of tubing may be used with substantially no more difficulty than a short section. This feature isVeryi' important,

for the voltage drop or resistance of the tube depends on the distance between the pools or, in effect, the length of the duct or arm. Consequently, it is substantially no more difiicult or costly to produce a tube for higher potential drops than to produce one for lower drops. On the other hand, the cost of tubes hitherto used for the same purpose varies greatly according to their voltage drops, due to the many variations necessary and parts used in the construction of these tubes. A concave sheet electrode 20 of any suitable material, is disposed against said envelope opposite the pool l5 and out of direct contact therewith to act as an external igniter. Of course, a similar electrode may be provided for the ball M, if desired. a a a The external igniter electrode 20 is especially useful and convenient for self ignition as shown in circuits herein, but it is to be understood that ignition may be eifected by any source of current connected to the igniter electrode and the pool associated therewith. Such a source must, of course, be capable of igniting the electrode, but its timing may depend on the use to which the tube is put. For example, if the main current is to be at less than 2500 volts (too low for normal self ignition) an auxiliary source at 3000 volts may be provided for, the electrode and pool.

The sizes of the sphere Ila and ball l4 may be varied according to the use of the tube. They may be of equal size or either one larger than the other. However, when the pool in one ball functions more frequently as a cathode, that ball or sphere is preferably larger, so as to provide greater surface for heat dissipation. For example, in Figure 5, the sphere He is larger than balls I4.

I prefer mercury pool electrodes, as the mercury is a getter for absorbing undesirable constituents from the envelope walls and the vapor space.

The external igniter electrode 20 is especially suited for self ignition, as will be explained later herein, but an internal igniter 202', as shown in Figure 3, and my Patent No. 2,287,541 may be used, where conditions of safety and control make it desirable.

For full wave rectification of single phase current or for half wave rectification in one part and discharge in the other part, I prefer a double armed tube Iflb, having a hollow sphere lib, as shown in Figure 4. For full wave rectification, the number of electrodes or igniters, shown at 20 and 20 are equal to the number of anodepools l5 and I6. While I prefer to ignite the central pool l5, my tube will operate if the ignition is effected at pools [6, since there is no difference in the composition of the pools and either may function as cathode or anode. Because of this fact, flash back which is extremely injurious to conventional tubes, does not affect m tube.

The central cathode portion may be provided with almost any number of arms and anode members, as shown in Figure 5. Six anodes are shown in this instance, since three'phase current can be completely rectified with such a tube. For other polyphase currents, the number of anodes may be varied accordingly.

A circuit, as shown in Figure 6, shows two uses of mytube, wherein a source of alternating current 2|, 22 is connected to a transformer 24, having a center-tapped secondary provided with two end terminals 25, 26 and a center terminal 28.

With this I use my tube of Figure 4 comprising an envelope, having therein three electrically separated pools of mercury l6, l5, l6, each in common contact with ionizable mercury vapor and two separated exterior igniter electrodes 20, 20' disposed against the envelope near the center pool [5 and dielectrically separated from the latter. One end terminal 25 of the secondary is connected to the first pool [6 and one electrode 20, and the other end terminal 26 is connected to the third pool I 6 and the other electrode 20'. In this arrangement the tube I0b acts as a selfigniting full wave rectifier for charging a condenser 29 connected in series with the center pool l5 and the center terminal 28.

Of course, a timed external source of current might be connected to the electrode and pool of each half of the tube to effect ignition, as shown in my Patent 2,287,544. Such a source would normallybe used if the main voltage across the tube is less than 2500 volts. The condenser may be discharged through a tank circuit 30, shown in heavy lines, comprising the mercury vapor discharge tube Hla and a reactor or inductor 31 in series therewith across said condenser.

The igniterelectrode 20" may be connected, as shown at 32, between the condenser and reactor or to the pool l6". The igniter 20 may be connected to a source of current independent of the tank circuit, as shown in my Patent No. 2,287,542 in Figure 3; alsoan internal igniter may be used as in Figure 1 therein.

My tube shown in Figure 5 may be used for three phase full rectification, as shown in Figure 7, wherein a source of three phase current L1, L2, La, is connected to a three phase transformer 24', having three secondaries each provided with two end terminals E1, E2, E3, E4, E5, E6, and a center tap terminal C1, C2, C3. The spider shaped envelope of insulating material has a central hollow portion Ilc, six hollow arms I2 extending from said portion and provided with ducts communicating with the space I I0 of said portion, and a hollow member l4 mounted on the outer end of each arm and having a space therein communicating with the ducts. A pool I50 of mercury, as shown in Figure 5, is disposed in said central portion and a similar pool H3 in each of said hollow members and separated from each other, but capable of being electrically connected by controlled ionization of mercury vapor within the envelope and in common contact with each pool.

The six secondary end terminals E1, E2, E3, E4,

, E5, and E6, are respectively connected to the six pools in said hollow members [4. While I show adjacent pools connected to the same secondary, any other arrangement of connection may be used. Means for igniting the central pool comprises six separated exterior igniter electrodes 20c, similar to those of Figure 2, disposed against said central portion near the pool therein, and each connected to one Of each of the pools in said members. In normal use the three center taps connected together constitute one terminal for the rectified current, while the central pool constitutes the other terminal.

While my circuit of Figure '7 shows igniter electrodes 200 as being energized by the same current as that being rectified, the ignition may be effected by an auxiliary igniter current, the timing of which may be controlled by any known means, as shown in my Patent 2,287,544.

I may use one-half of the tube shown in Figure 4 for half wave rectification of the current and the other half for discharge, as shown in Figure 8 in a manner similar to that shown in Figure 6, but Without full rectification.

Thus, in Figure 8 one terminal 25 is connected to the first and third pools l6, it, to the electrode 20 and to one end of the inductor 31. The condenser 29 is connected on the side to the second pool l5 on the other side to switch means 34 for connecting the condenser to terminal 28 for charging the condenser and then by reversing the switch completing an oscillatory circuit through the condenser, the inductor and discharge tube.

With envelopes of good grade glass about 0.1 inch thick I have found self ignition to be reliable when the potential difference across the external igniter and the cathode pool are as low as 2800 volts. When voltages under 2500 are met with, I may use the standard igniters well known in the art, as well as my exterior electrode operated by auxiliary currents at sufficiently high voltage. With external self igniters, the ionization inherently occurs with proper timing, so that my circuits may be substantially free of auxiliary timers.

What I claim as my invention and desire to secure by Letters Patent of the United States, is:

1. An electronic tube, comprising a dumb-bell shaped hollow envelope, having a hollow cylindrical middle portion and two substantially spherical hollow end portions of increased diameter thereon; interior electrodes in each end portion; and an electrode exterior of the envelope and close enough to one of said interior electrodes to form a condenser therewith.

2. A mercury arc tube, comp-rising an envelope of insulating material and having cathode and anode portions, said portions being provided with internal upwardly open recesses, a common vapor space above said recesses; pools of mercury in said recesses, each pool being separated from the other, and external terminal means in contact with said ools.

3. A rectifying or discharge tube, comprising an envelope of insulatin material, having a, substantially spherically shaped hollow portion; one or more hollow cylindrical arms on said portion, lying in substantially the same plane, and forming ducts communicating with the interior of said hollow portion; a hollow ball on the outer end of each arm, the interior of the balls being in communication with each of said ducts; pools 4. A rectifying or discharge tube, comprising "an envelope of heat resisting insulatin material, having a substantially spherically shaped hollow portion; a hollow cylindrical arm on said portion and forming a duct communicating with the interior of the hollow portion, a hollow ball on the outer end of said arm, the interior of the ball being in communication with said duct, pools of mercury, one in said hollow portion and another in said ball; the duct being at a higher level than the upper level of the pools, so that pools are electrically separated except by ionizable gaseous conduction; external terminals passing through the envelope and in direct contact with each of the pools; and an igniter electrode for one of said pools, said electrode being disposed against the exterior face of said envelope opposite said one of the poo-1s.

5. A discharge tube comprising an envelope of heat resisting insulating material having a substantially spherically shaped hollow portion, a hollow cylindrical arm raised at the mid-portion thereof and developed on said portion and forming a duct communicating with the interior of the hollow portion, a hollow ball on the outer end of said arm, the interior of the ball being in communication with said ducts, a pool of mercury in said hollow portion and in said ball, the duct being at a higher level than the upper level of the pools, the raised mid-portion causing condensed mercury to drain to the nearer pool, the pools being electrically separated except by ionizable gaseous conduction from one pool to the other, external terminals passing through the envelope and in direct contact with each of the pools, and an igniter electrode for one of said pools and comprising an electrode disposed against the exterior face of said envelope opposite one of the said pools.

ALFRED VANG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,064,687 Hewitt June 10, 1913 1,163,706 Thomas Dec. 14, 1915 1,593,373 Van Der Bil'l July 20, 1926 1,906,037 Zecher et al Apr. 25, 1933 2,241,968 Suits May 13, 1941 2,287,541 Vang June 23, 1942 1,889,079 Sperti Nov. 29, 1932 2,107,934 De Blieux Feb. 8, 1938 2,165,075 Slepian July 4, 1939 2,347,715 Spencer May 2, 1944 

